<!DOCTYPE html>
<html>
  <body>
    <!--  根节点  -->
    <div id="root"></div>

    <!--    -->
    <script src="./react.development.js"></script>
    <script src="./react-dom.development.js"></script>

    <!--  组件  -->
      <script  src="./index.js"></script>

    <!--  挂载根节点  -->
    <script>
      ReactDOM.render(React.createElement(Index), document.querySelector('#root'));
    </script>
  </body>
</html>